Chemical Engineering Journal,
Journal Year:
2024,
Volume and Issue:
484, P. 149478 - 149478
Published: Feb. 7, 2024
ThermoCatalytic
Decomposition
of
methane
(TCD)
has
shown
great
potential
for
synthesis
valuable
carbon
nanomaterials
as
well
hydrogen
production,
however
due
to
the
importance
phenomena
operating
at
different
scales,
it
is
a
complex
process
model
and
predict.
During
TCD
decomposed
gas
solid
carbon.
Carbon
accumulated
on
catalyst
particle
leads
larger
but
less
active
particles.
In
this
study,
Computational
Fluid
Dynamics-Discrete
Element
Method-Multi
Grain
Model
(CFD-DEM-MGM)
was
employed
investigate
two
catalytic
fluidized
bed
reactors
with
same
dimensions.
Case-1
involved
batch
particles
staying
in
reactor
during
process,
while
Case-2
featured
continuous
removal
from
bottom
introduction
fresh
side.
Results
showed
that
had
lower
growth
reduced
deactivation
limited
residence
time,
yet
demonstrated
higher
production
conversion.
Case-1,
particles,
experienced
bubble
formation,
removal/introduction
enhanced
solids
mixing.
Internal
diffusion
limitations
affected
performance,
emphasizing
CFD-DEM-MGM
model's
optimizing
design
gas-solid
contacting
process.
AIChE Journal,
Journal Year:
2024,
Volume and Issue:
70(5)
Published: March 12, 2024
Abstract
The
understanding
of
complex
fluidization
hydrodynamics
and
chemical
reactions
in
biomass
fast
pyrolysis
fluidized
bed
reactors
is
lacking
requires
further
investigation.
It
urgent
to
develop
accurate
mathematical
models
capable
describing
the
multiphase
reaction
system
pyrolysis.
A
comprehensive
multiscale
model
based
on
coarse‐grained
discrete
element
method
(DEM)‐computational
fluid
dynamics
(CFD)
was
developed
open‐source
MFiX
code.
incorporates
detailed
kinetics
an
intraparticle
model.
To
validate
model,
measurements
were
conducted
a
pyrolyzer,
including
quantifying
segmental
pressure
drop
along
height
determining
yields
compositions
gas,
liquid,
solid
products.
particle
mixing
segregation,
axial
distribution
residence
time,
Lacey
index,
products
investigated.
study
provides
experimental
theoretical
foundations
for
designing
advancing
thermochemical
conversion.
Chemical Engineering Journal,
Journal Year:
2021,
Volume and Issue:
429, P. 132415 - 132415
Published: Sept. 14, 2021
Tons
of
products
are
facilitated
through
powder
mixing
processes.
The
quality
the
final
is
highly
influenced
by
state.
Hence,
detailed
information
about
state
necessary
to
improve
quality.
Recent
remarkable
advancements
in
computer
hardware
enable
evaluation
via
numerical
simulation.
Discrete
Element
Method
(DEM)
frequently
used
simulations,
where
computational
particle
shapes
typically
modeled
a
spherical
body.
On
other
hand,
not
all
industries
spherical,
and
structure
industrial
mixers
generally
complex.
Thus,
when
DEM
applied
an
mixer,
modeling
shape
complex
may
be
taken
into
consideration.
In
present
study,
innovative
model
newly
developed
simulate
non-spherical
particles
mixer.
Here,
ellipsoidal
equation,
mixer
using
Signed
Distance
Function
(SDF),
wall
boundary
flexibly
scalar
field.
This
approach
referred
as
DEM/SDF.
current
adequacy
applicability
DEM/SDF
demonstrated
following
steps.
First,
compatibility
with
SDF
soft
linear
spring
validation
tests.
Subsequently,
effect
on
progress
ribbon
examined.
Through
computations,
shown
insignificant
Consequently,
applicable
mixing,
therefore,
will
contribute
optimization
design
operational
conditions
chemical,
food,
pharmaceutical
engineering
fields.
